Do synaesthetic colours act as unique features in visual search?

Edquist, J, Rich, AN, Brinkman, C and Mattingley, JB (2006) Do synaesthetic colours act as unique features in visual search?. Cortex, 42 2: 222-231. doi:10.1016/S0010-9452(08)70347-2

Author Edquist, J
Rich, AN
Brinkman, C
Mattingley, JB
Title Do synaesthetic colours act as unique features in visual search?
Journal name Cortex   Check publisher's open access policy
ISSN 0010-9452
Publication date 2006-01-01
Year available 2006
Sub-type Article (original research)
DOI 10.1016/S0010-9452(08)70347-2
Open Access Status
Volume 42
Issue 2
Start page 222
End page 231
Total pages 10
Place of publication Milano
Publisher Masson Divisione Periodici
Language eng
Abstract For individuals with grapheme-colour synaesthesia, letters, numbers and words elicit vivid and highly consistent colour experiences. A critical question in determining the mechanisms underlying the phenomenon is whether synaesthetic colours arise early in visual processing, prior to the allocation of focused attention, or at some later stage following explicit recognition of the inducing form. If the synaesthetic colour elicited by an achromatic target emerges early in visual processing, then the target should be relatively easy to find in an array of achromatic distractor items, provided the target and distractors elicit different synaesthetic colours. Here we present data from 14 grapheme-colour synaesthetes and 14 matched non-synaesthetic controls, each of whom performed a visual search task in which a target digit was distinguished from surrounding distractors either by its unique synaesthetic colour or by its unique display colour. Participants searched displays of 8, 16 or 24 items for a specific target. In the chromatic condition, target and distractor digits were presented in different colours (e.g., a yellow '2' amongst blue '5's). In the achromatic condition, all digits in the display were black, but targets elicited a different synaesthetic colour from that induced by the distractors. Both synaesthetes and controls showed the expected efficient (pop-out) search slopes when the target was defined by a unique display colour. In contrast, search slopes for both groups were equally inefficient when the target and distractors were achromatic, despite eliciting distinct colours for the synaesthetes under normal viewing conditions. These results indicate that, at least for the majority of individuals, synaesthetic colours do not arise early enough in visual processing to guide or attract focal attention. Our findings are consistent with the hypothesis that graphemic inducers must be selectively attended to elicit their synaesthetic colours.
Keyword Behavioral Sciences
visual search
selective attention
subjective report
serial search
Q-Index Code C1
Institutional Status Non-UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: Excellence in Research Australia (ERA) - Collection
Queensland Brain Institute Publications
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Citation counts: TR Web of Science Citation Count  Cited 55 times in Thomson Reuters Web of Science Article | Citations
Scopus Citation Count Cited 61 times in Scopus Article | Citations
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Created: Thu, 18 Oct 2007, 00:46:03 EST